The operating principle of battery electric vehicle is that an electric motor converts electrical energy into kinetic energy which is subsequently transferred to a wheel/wheels to drive a battery electric vehicle. When the electric motor rotates forward, the electricity of the batteries is consumed to drive the battery electric vehicle moving forward. On the other hand, when the battery electric vehicle brakes, the electric motor, which is appropriately configured, can act as an electric generator which converts the kinetic energy caused from braking into electrical energy, by which the generated electrical energy is stored back to the batteries. Accordingly, a mechanism of energy recycle can be achieved.
However, for a traditional battery electric vehicle, energy recycling only happens for few circumstances, such as the battery electric vehicle being in a situation of braking or going downhill. Therefore, the proportion of recycled energy is relatively small, which causes the battery electric vehicle to have poorer battery life and weaker competition compared with a hybrid vehicle. In other words, the lifespan of electric vehicles battery has not yet been improved radically.